Integrated rf mems on ate loadboards for smart self rf matching

ABSTRACT

In a testing device, a method for implementing automatic RF port testing. The method includes attaching a device under test having a plurality of RF pins to a load board, dynamically tuning a plurality of RF ports of the load board to the plurality of RF pins, and automatically matching the plurality of RF ports to the plurality of RF pins with respect to impedance. The method further includes implementing an RF port testing process on the device under test.

FIELD OF THE INVENTION

The present invention is generally related to computer system testequipment.

BACKGROUND OF THE INVENTION

RF devices continue to be highly integrated with multiple bands,multiple standards and often with greater than 20 RF ports on a singledevice. The current time required to match such devices using thetraditional manual approach can be two or three weeks. Combine this withtoday's massive parallel test capabilities of ATE (×4, ×8, and even ×16)and the time required to properly match ˜80⁺ RF ports across multiplesites can easily surpass several weeks.

RF matching has largely remained unchanged for the past several decades.The engineer typically employs an iterative, manual, time-intensiveapproach of placing and removing various LC components onto the loadboard. After each iteration a VNA is employed to measure the new match.This process repeats until the best match (typically as close to 50Ohms) is found. This method is completely incapable of scaling to meetthe needs of the modern industrial manufacturing processes.

Thus there exists a need for next-generation automated high-speedtesting. There exists a need for technology that delivers unprecedentedtest time and test cost reductions.

SUMMARY OF THE INVENTION

In a testing device, a method for implementing automatic RF porttesting. The method includes attaching a device under test having aplurality of RF pins to a load board, dynamically tuning a plurality ofRF ports of the load board to the plurality of RF pins, andautomatically matching the plurality of RF ports to the plurality of RFpins with respect to impedance. The method further includes implementingan RF port testing process on the device under test.

In one embodiment, the testing device comprises an RF electronicsdevice.

In one embodiment, a plurality of RF electronics devices are testedsimultaneously.

In one embodiment, the load board further comprises an RF MEMs impedancematching device.

In one embodiment, wherein the dynamically tuning of the plurality of RFports is software controlled and configured.

In one embodiment, the load board further comprises an RF MEMs impedancematching device having a tunable impedance matching circuit.

In one embodiment, the load board further comprises programmablecapacitive elements implemented in a CMOS RF MEMs impedance matchingstructure.

In one embodiment, the present invention is implemented as anon-transitory computer readable memory having computer readable codewhich when executed by a computer system causes the computer system toimplement a method for implementing automatic RF port testing. Themethod includes attaching a device under test having a plurality of RFpins to a load board, dynamically tuning a plurality of RF ports of theload board to the plurality of RF pins, and automatically matching theplurality of RF ports to the plurality of RF pins with respect toimpedance. The method further includes implementing an RF port testingprocess on the device under test.

The foregoing is a summary and thus contains, by necessity,simplifications, generalizations and omissions of detail; consequently,those skilled in the art will appreciate that the summary isillustrative only and is not intended to be in any way limiting. Otheraspects, inventive features, and advantages of the present invention, asdefined solely by the claims, will become apparent in the non-limitingdetailed description set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements.

FIG. 1 shows a diagram illustrating a speed/distance overlay of wirelessstandards as used by embodiments of the present invention.

FIG. 2 shows a functional block diagram of an RF MEMs Circuit inaccordance with one embodiment of the present invention.

FIG. 3 shows a principal block diagram of an RF MEMs circuit device inaccordance with one embodiment of the present invention.

FIG. 4 shows a characterization results diagram of the normalized targetcapacitance in accordance with one embodiment of the present invention.

FIG. 5 shows a diagram of an RF MEMs device integrated onto a longboardin accordance with one embodiment of the present invention.

FIG. 6 shows an exemplary computer system 600 according to oneembodiment.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. While the invention will be described in conjunction with thepreferred embodiments, it will be understood that they are not intendedto limit the invention to these embodiments. On the contrary, theinvention is intended to cover alternatives, modifications andequivalents, which may be included within the spirit and scope of theinvention as defined by the appended claims. Furthermore, in thefollowing detailed description of embodiments of the present invention,numerous specific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be recognizedby one of ordinary skill in the art that the present invention may bepracticed without these specific details. In other instances, well-knownmethods, procedures, components, and circuits have not been described indetail as not to unnecessarily obscure aspects of the embodiments of thepresent invention.

Notation and Nomenclature

Some portions of the detailed descriptions, which follow, are presentedin terms of procedures, steps, logic blocks, processing, and othersymbolic representations of operations on data bits within a computermemory. These descriptions and representations are the means used bythose skilled in the data processing arts to most effectively convey thesubstance of their work to others skilled in the art. A procedure,computer executed step, logic block, process, etc., is here, andgenerally, conceived to be a self-consistent sequence of steps orinstructions leading to a desired result. The steps are those requiringphysical manipulations of physical quantities. Usually, though notnecessarily, these quantities take the form of electrical or magneticsignals capable of being stored, transferred, combined, compared, andotherwise manipulated in a computer system. It has proven convenient attimes, principally for reasons of common usage, to refer to thesesignals as bits, values, elements, symbols, characters, terms, numbers,or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the present invention,discussions utilizing terms such as “processing” or “accessing” or“executing” or “storing” or “rendering” or the like, refer to the actionand processes of a computer system (e.g., computer system 400 of FIG.4), or similar electronic computing device, that manipulates andtransforms data represented as physical (electronic) quantities withinthe computer system's registers and memories into other data similarlyrepresented as physical quantities within the computer system memoriesor registers or other such information storage, transmission or displaydevices.

Embodiments of the Invention

Embodiments of the present invention implement integrated RF MEMs on ATE(Automatic Test Equipment) loadboards for smart self RF matching. Asused herein, the term “MEMs” micro electro mechanical systems (e.g.,devices and structures) made using micro-fabrication techniques.Embodiments of the present invention employ RF MEMs to largely automatethe RF matching process used on load boards.

RF matching has largely remained unchanged for the past several decades.The engineer typically employs an iterative, manual, time-intensiveapproach of placing and removing various LC components onto the loadboard. After each iteration a measurement device is employed to measurethe new match. This process repeats until the best match (e.g.,typically as close to 50 Ohms) is found. For a single port device, thismanual approach, albeit cumbersome, was “good enough”, and acceptable tothe marketplace.

RF devices continue to be highly integrated with multiple bands,multiple standards and often with greater than 20 RF ports on a singledevice. The current time required to match such devices using thetraditional manual approach can be two or three weeks. Combine this withtoday's massive parallel test capabilities of ATE (e.g., ×4, ×8, andeven ×16) and the time required to properly match approximately 80 ormore RF ports across multiple sites can easily surpass several weeks.Embodiments of the present invention eliminate the traditional manualmatching approach, which was unsustainable in the electronicsmanufacturing industry.

Embodiments of the present invention solve a number of problems in theelectronics manufacturing industry. One such problem is the “NegativeTime-to-Market” problem. With time to market expectations shrinking tojust a few months, the industry cannot sustain such a high T™ cost.Another such problem is the “Higher Yield Loss” problem. The manualtuning of multiple ports across multiple sites and multiple testersleads to correlation issues that leads to yield loss and increases cost.These problems are avoided by the automated RF matching process ofembodiments of the present invention.

FIG. 1 shows a diagram illustrating a speed/distance overlay of wirelessstandards as used by embodiments of the present invention. The explosivegrowth of Wi-Fi and VoIP enterprise service is challenging the existinglandscape. LTE roll-out is in progress and demand for more services,higher speeds and lower costs has generated a myriad of standards, asshown in FIG. 1. The mobile communications market is one of the world'sfastest growing markets in terms of both products and services. Thehandset market has more than 4 billion subscribers worldwide.

Accordingly, the net result is the rapid evolution of multi-band,multi-standard wireless devices. With the increased number of frequencybands, number of RF ports, and number of sites, the loadboard complexityhas exponentially grown. Despite significant advances in ATE hardwareand software, the conventional RF matching of the load boards to the ATEinterfaces has largely remained unchanged for decades. Conventionally,it is left to the test engineer to manually match each RF port on theloadboard.

Embodiments of the present invention advantageously introduces theconcept of Smart Loadboards™. Embodiments of the present invention useintegrated RF MEMs tunable impedance matching network technology with anSPI interface to eliminate the conventional lengthy, tedious andcumbersome manual RF tuning process. By integrating this technology,embodiments of the present invention effectively provides theelectronics manufacturing industry with Smart Loadboards™ capable ofself-matching and dynamic tuning Embodiments of the present inventionaddress a number of the industry's problems and provide several keybenefits:

1) Smart Loadboards™ Improve Time-to-Market

a. The Smart Loadboards™ dramatically reduce Time-to-Market byself-tuning to the optimum match. Self-tuning eliminates the recursivemanual trial and error process.

b. Smart Loadboards™ simplify and improve site-to-site correlation.Smart algorithms can be employed to optimize matching from site-to-site.

c. Tester to tester correlation simplified and automated

2) Reduces Cost

a. Site to site correlation made easier

b. Variations reduced from greater tuning resolution

c. Eliminates the need for expensive RF tuning expert

3) Enhances Yield

a. Greater tuning resolution and range improves yield

b. Eliminates load board variations introduced from manual process

c. As Loadboards™ are interchanged from tester to tester, SmartLoadboards™ can automatically adjust their match for tester to testervariations.

FIG. 2 shows a functional block diagram of an RF MEMs Circuit inaccordance with one embodiment of the present invention. In the FIG. 2embodiment, the WS2017 tunable impedance matching circuit is used. It isdesigned to be inserted in the RF signal chain between the DUT (DeviceUnder Test) and the ATE RF ports. In this embodiment, the tuning rangeis from 824 MHz to 2170 MHz (e.g., the current generation).

The innovative tunable capacitor technology combines excellent RFperformance from a high-Q parallel plate capacitor and fixed inductancenetwork with versatile digital control of the capacitance values. Theentire TX/RX signal chains can now be optimized resulting in superiorperformance, lower cost, and faster time to market. The impedance matchis digitally controlled by the programmable capacitive elementsimplemented in CMOS-RF-MEMS structure. This is shown in the FIG. 2functional block diagram.

Features of this new Integrated RF MEMS Technology include:

True single chip CMOS tuner

Frequency range 824 MHz-2170 MHz

Corrects VSWR up to 20:1

Covers GSM850, EGSM, DCS, PCS and WCDMA

0.125 pF step size

Software controlled

FIG. 3 shows a principal block diagram of an RF MEMs circuit device inaccordance with one embodiment of the present invention. In the FIG. 3embodiment, an array of integrated capacitors can be programmed usingthe integrated SPI, I2C and other supported standards. Using theintegrated VNA capabilities of testers in combination with theintegrated RF MEMs technology and digital control, the loadboard becomesa Smart Loadboard™. Self tuning software having smart algorithms willautomatically tune and match the loadboard for all ports and for allsites. The process is automatic, self-correcting, and requires just afew minutes versus the several weeks of the manual process.

FIG. 4 shows a characterization results diagram of the normalized targetcapacitance in accordance with one embodiment of the present invention.The left-hand side of FIG. 4 shows normalized mean capacitance inpico-farads. The right-hand side of FIG. 4 shows a standard deviation ofcapacitance as a percent of the mean.

In this manner, embodiments of the present invention have introduced theconcept of Smart Loadboards™ and shown that by using integrated RF MEMStechnology on ATE load boards, that the time-to-market, and cost of test(COT) can be greatly reduced. Additionally, superior performance, andless variation from site-to-site as well as tester-to-tester improvestest yield and further reduces cost.

FIG. 5 shows a diagram of an RF MEMs device integrated onto a longboardin accordance with one embodiment of the present invention. In adifferent embodiment, integrating the RF MEMs onto an actual load boardwith physical DUT can be implemented in a different manner. In suchdifferent embodiments, the integration of the RF MEMs onto Advantestload boards with a physical DUT will be further optimized.

Computer System Platform:

FIG. 6 shows an exemplary computer system 600 according to oneembodiment. Computer system 600 depicts the components of a basiccomputer system providing the execution environment for certainhardware-based and software-based functionality for the above describedembodiments. Computer system 600 can be implemented as, for example, aserver computer system, workstation computer system, desktop computersystem, or laptop computer system. Similarly, computer system 600 can beimplemented as a handheld device. Computer system 600 typically includesat least some form of computer readable media (e.g., computer readablestorage medium 601). Computer readable media can be a number ofdifferent types of available media that can be accessed by computersystem 600 and can include, but not limited to, computer storage media.

In its most basic configuration, computer system 600 typically includesprocessing unit 603 and a computer readable storage medium 601.Depending on the exact configuration and type of computer system 600that is used, memory 601 can be volatile (e.g., such as DRAM, etc.) 601a, non-volatile 601 b (e.g., such as ROM, flash memory, etc.) or somecombination of the two. Similarly, the memory 601 can comprise otherdevices besides solid-state devices, such as, for example, magneticdisk-based media, optical media, or the like.

Additionally, computer system 600 can include other mass storage systems(e.g., removable 605 and/or non-removable 607) such as magnetic oroptical disks or tape. Similarly, computer system 600 can include inputdevices 609 and/or output devices 611 (e.g., such as a display).Computer system 600 can further include network connections 613 to otherdevices, computers, networks, servers, etc. using either wired orwireless media. As all of these devices are well known in the art, theyneed not be discussed in detail.

It should further be noted, that the computer system 600 can have some,most, or all of its functionality supplanted by a distributed computersystem having a large number of dispersed computing nodes, such as wouldbe the case where the functionality of the computer system 600 is partlyor wholly executed using a cloud computing environment.

The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and many modifications andvariations are possible in light of the above teaching. The embodimentswere chosen and described in order to best explain the principles of theinvention and its practical application, to thereby enable othersskilled in the art to best utilize the invention and various embodimentswith various modifications as are suited to the particular usecontemplated. It is intended that the scope of the invention be definedby the claims appended hereto and their equivalents.

What is claimed is:
 1. In a testing device, a method for implementingautomatic RF port testing, comprising: attaching a device under testhaving a plurality of RF pins to a load board; dynamically tuning aplurality of RF ports of the load board to the plurality of RF pins;automatically matching the plurality of RF ports to the plurality of RFpins with respect to impedance; and implementing an RF port testingprocess on the device under test.
 2. The method of claim 1, wherein thetesting device comprises an RF electronics device.
 3. The method ofclaim 1, wherein a plurality of RF electronics devices are testedsimultaneously.
 4. The method of claim 1, wherein the load board furthercomprises an RF MEMs impedance matching device.
 5. The method of claim1, wherein the dynamically tuning of the plurality of RF ports issoftware controlled and configured.
 6. The method of claim 1, whereinthe load board further comprises an RF MEMs impedance matching devicehaving a tunable impedance matching circuit.
 7. The method of claim 1,wherein the load board further comprises programmable capacitiveelements implemented in a CMOS RF MEMs impedance matching structure. 8.A non-transitory computer readable memory having computer readable codewhich when executed by a computer system causes the computer system toimplement a method for implementing automatic RF port testing,comprising: attaching a device under test having a plurality of RF pinsto a load board; dynamically tuning a plurality of RF ports of the loadboard to the plurality of RF pins; automatically matching the pluralityof RF ports to the plurality of RF pins with respect to impedance; andimplementing an RF port testing process on the device under test.
 9. Thecomputer readable media of claim 8, wherein the testing device comprisesan RF electronics device.
 10. The computer readable media of claim 8,wherein a plurality of RF electronics devices are tested simultaneously.11. The computer readable media of claim 8, wherein the load boardfurther comprises an RF MEMs impedance matching device.
 12. The computerreadable media of claim 8, wherein the dynamically tuning of theplurality of RF ports is software controlled and configured.
 13. Thecomputer readable media of claim 8, wherein the load board furthercomprises an RF MEMs impedance matching device having a tunableimpedance matching circuit.
 14. The computer readable media of claim 8,wherein the load board further comprises programmable capacitiveelements implemented in a CMOS RF MEMs impedance matching structure. 15.In a testing device, a method for implementing automatic RF porttesting, comprising: attaching a device under test having a plurality ofRF pins to a load board, wherein the load board further comprisesprogrammable capacitive elements implemented in a CMOS RF MEMs impedancematching structure; dynamically tuning a plurality of RF ports of theload board to the plurality of RF pins; automatically matching theplurality of RF ports to the plurality of RF pins with respect toimpedance; and implementing an RF port testing process on the deviceunder test.
 16. The method of claim 15, wherein the testing devicecomprises an RF electronics device.
 17. The method of claim 15, whereina plurality of RF electronics devices are tested simultaneously.